I have a lenovo y510p with a core i7 4th generation processor with intel hd 4600 graphics, along with a nvidia 755m graphics card and windows 8.1. Most games I can run really well and have no issues, but with some, especially Civilization iv and steam indie games, I get memory warnings and then my computer crashes with the error code driver_irql_not_less_or_equal igdkmd64.sys. I tried to install the latest driver for windows 8.1 but my computer said the drivers were already up to date, so I uninstalled the current driver and tried to install the new one but it says my system does not meet the minimum requirement. I also tried disabling the intel hd graphics, but those games then used my basic graphics adapter instead of the Nvidia, even though i specified in the control panel that these programs should use the Nvidia card. Please help.